The hair follicle as a target for gene therapy

The hair follicle possesses progenitor cells required for continuous hair follicle cycling and for epidermal keratinocytes, melanocytes and Langerhans cells. These different cell types can be the target of topical gene delivery in the skin of the mouse. Using a combination of liposomes and DNA, we demonstrate the feasibility of targeting hair follicle cells in human scalp xenografts. We consider liposome composition and stage of the hair cycle as important parameters influencing transfection of human hair follicles. Transfection is possible only during the early anagen phase. Factors and obstacles for the use of gene therapy in treating alopecia and skin diseases are discussed. A theoretical framework for future treatment of cutaneous and systemic disorders using gene therapy is presented.